Halogen substituted mono-aromatic phenolic reserving agents for acrylonitrile polymer base fibers



linited States Patent HALOGEN SUBSTITUTED MONO-AROMATIC Pm:- NOLICRESERVING AGENTS FoR ACRYLONI- TRILE POLYNIER BASE FIBERS William M.Blankenship, Williamsburg, and Allan R. Wirth, Newport News,Va.,assignors to TheiDow Chemical Company, Midland, Mich., a corporation ofDelaware No Drawing. pplication July 29, 1958 Serial No. 751,652

21 Claims. (Cl. 8-21) A valuable and significant contribution to thesynthetic fiber art has been the development and provision of thenitrile alloy class of fibers. Such man-made fibers are comprisedessentially of an acrylonitrile polymer base which contains in thepolymer molecule at least about 80 weight percent of acrylonitrile,advantageously polyacrylonitrile, which has been beneficially modifiedwithout sacrifice of or compromise in its basic fiber properties byalloying the acrylonitrile polymer base, as it were, with beneficialadditaments or constituents that are adapted to achieve one or moreameliorative ends for the fiber product. Primarily, and of exceptionalbenefit, the nitrile alloy fibers contain appropriate functionalcomponents that render the fiber product remarkably and permanentlyreceptive of many of a Wide variety of dyestuffs. Because of this,nitrile alloy" fibers are readily dyeable to deep and level shades oflasting coloration by practice of ordinary dyeing techniques andprocedures, using the usual materials and operations for the purpose. Bytheir superior attributes in these as'well as other particulars, thenitrile alloy fibers are clearly and easily distinguishable from theconventional prototype acrylonitrile polymer fibers (including the usualand well known copolymeric varieties) with which the art is familiar andwhich are oftentimes referred to and known as being acrylic fibers.

As paradoxal as it may seem, there are instances wherein the exceptionaland capacious receptivity to dyestuffs of nitrile alloy fibers mightadvantageously be restrained or partially or completely diminished, inorder that such characteristics of the fiber product might be basicallyaltered so as to provide it with a partial or complete degree ofresistance to becoming stained or colored with dyestuffs.

For example, if a stain-free, white fiber product is desired from anitrile alloy material, such as a cloth or fabric article, it would beadvantageous for the nitrile alloy to be provided in such a form as tobe capable of complete resistance to becoming stained or colored by dyesor other color-imparting substances with which the nitrile alloy maycome in contact.

Of at least commensurate practical significance is the problem ofproducing white or two-toned effects on nitrile alloy fibers when theyare dyed in the presence of other fibers, such as cellulosics or wooland other proteinous fibers (both natural and artificial or synthetic inorigin) with which the nitrile alloy fibers may be blended as well asthat of achieving union-dyeing or t advantages, may be achieved pursuantto the compre- 2 of the fibers in the blend) to the same or sequentiallythe same uniform and balanced blend of coloration of each of the fibersin the blend. For purposes of achieving the immediately above-mentionedends, it would be advantageous, as is apparent, for nitrile alloy fibersto be provided in such a form that they would have only a partialresistance to or reserving action against dye stuffs and coloringagents, depending on whether diverse or equal tones of coloration aredesired in the dyed blend in which the nitrile alloy fiber is contained.7

Thus, it would be advantageous, and it is the aim andconcern of thepresent invention, to provide nitrile alloy fibers, altered or modifiedwith respect .to their receptivity for dyestuffs over a range extendingfromthe capability of such altered forms of nitrile alloy fibers.

were, from slightly to considerable in inverse proportion to theiraltered degree of dye-receptivity.

It is the principal object of the present invention to.

provide and make available highly efficacious reserving (ordye-resisting) agents specific in their limiting effect or action fromthe dye-receptivity of nitrile alloy fibers so as to be useful for theseveral indicated and related purposes upon and in conjunction withnitrile alloy fibers, particularly those comprising polymerized N-vinyllactam (especially N-vinyl pyrrolidone or N-vinyl caprolactam) orpolymerized N-vinyl-Z-oxazolidinone (including especially theunsubstituted and methyl and ethyl ring-substituted species)constituents as dye-receptive adjuvants for the fiber, including unmixednitrile alloy fibers as well as blends of nitrile alloy" fibers withcellulosic or proteinous fibers and yarn, thread, cord and the like andcloth or fabric constructed from such fibers or fiber blends.

Another object of the invention is to provide, as new and improvedarticles of manufacture, nitrile alloy" fibers, including such fibers inunmixed as well as in blended forms and textile articles constructedtherefrom, having their degree of dye-receptivity or susceptibility tocoloration or staining by dyes and the like controlled by modificationor alteration of their normal characteristics in such regards by meansof certain dye-resisting agents, as herein more fully delineated,applied to the fibers.

Still an additional object of the invention is to furnish a method ormeans for controlling the dye-receptivity of nitrile alloy fibers inunmixed or blended masses or in various constructed or fabricatedtextile articles or, as might be otherwise expressed, a new and improvedmethod for dyeing or controlling the dye receptivity of nitrile alloyfibers, especially when they are in blended cellulose or proteinousfiber-containing masses, so as to achieve and possibilitate tw0-tone orunion-dyeing effects.

Yet another object of the invention is to provide reserving agents fornitrile alloy fibers having excellent resistance to caustic solutions soas to provide fiber compositions comprised of the nitrile alloy fiberstreated with the agents that are capable of demonstrating unusualresistance to staining after dyeing and to discoloration of the fiberwhen it is subjected to highly basic solutions, such as those which arefrequently encountered in scouring operations and in some types ofdyeing procedures.

The above indicated objects, and corollary benefits and Patented Apr. 5,1960 lrension andpractice ofthepresent invention by treating a"nitrilealloy fiber' (particularly one of the herein indicated highly desirablevarieties) with a minor proportion of from about 0.1 ,to about -25weight percent, biased on the weight of the resulting composition anddepending upon the extent of dye-resistance or degree of controldesired, of a certain variety of halogen substituted mono-aromaticphenolic materials, as herein more fully illustrated, as a dye-reservingor dye-resisting agent that is applied to and is in intimate physicalcontact with the fiber at least during the treatment. As might beanticipated, the degree of control or resistance to dyeing or the extentof modification of the dye-receptivity of the nitrile alloy fiberthatmay be achieved is in proportion to the quantity of thedye reserving orresisting agent that isapplied thereto or employed for the treatment.

ln' this connection, not all of the presently contemplated halogensubstituted mono-aromatic phenolic reserving agent initially applied toor employed for treatment of the nitrile alloy fiber is generally ornecessarily aflixed in a permanent and wash-resistant manner to thefiber. The reserving agents are not without exception permanentlyadsorbed by the nitrile alloy in quantitative proportion to the relativeamount in which they are applied to or used for initial treatment of thefiber. A good proportion (frequently 60 weight percent or more) mayfrequently be washed, leached or extracted out of the fiber after (oreven during) the initial treatment by cold water or other solvent liquidwashes. It is diflficult to predict in all instances precisely andexactly how much of the presently contemplated reserving agent ispermanently and with positive substantivity affixed to the niti'ilealloy fiber in the practice of the present invention. Generally at leastabout 0.01 weight percent on the weight ofthe dry fiber (o.w.f.) andfrequently in the neighborhood of at least 0.05 percent is permanentlyadsorbed, incorporated in and retained by the nitrile alloy afterthetreatment and despite the extractive influence of water and mostother solvent washes. The mechanism of the presently contemplatedreserving agents apparently is independent of a quantitative, physicallypermanent adsorption but is thought to involve more of a blockingoutefliect of the dycstuff from the nitrile alloy comp sition. In anyevent, minor proportions of permanently and substantively retainedreserving agent of the aboveindicated order of magnitude are,surprisingly enough, adequate to produce the described anti-stainingcharacteristics in the treated nitrile alloy article. And, even moreremarkably, the degree of anti-staining efiect achieved (despite therelatively minute quantities of re serving agent that may be retainedwith true permanence inthe nitrile alloy article) is dependent upon anda function of the relative quantity of agent initially applied toandused to treat the fiber.

vThus, complete or practically complete resistance to dyeing andcoloration are generally afforded by heavier applications of ortreatments with the agent, such as those in the neighborhood of fromabout 10 to weight percent o.w.f. which, as indicated, is notnecessarily or even probably all permanently retained by the fiber. Apartial or appreciably enhanced resistance to dyeing (or decrease indye-receptivity) of the nitrile alloy fiber blends may be secured byusing a reserving quantity of the agent on and in the initial treatmentof the fiber that is between about 1 or 2 to about 10 percent by weighto.w.f., with the specific ultimate effect (notwithstanding permanentretention) of the agent again being proportional to the quantityemployed. Union-dyeing effects in blends of nitrile alloy fibers of thecellulosic or proteinous fibers may ordinarily be facilitated byutilizing application of or treatment with a balancing quantity of theagent between about 0.1 and 1.5 or 2 percent by weight o.w.f. (notnecessarily and probably not actually all permanently retained) in orderto promote excellent shade balancing of all the diverse filamentary 4components during the dyeing of the blend, especially when'the dyestuffsemployed have a propensity to" build up upon or disproportionately'colorthe nitrile alloy fiber in the blend, as is often the case with certaindirect or after-treated types of dyestuffs when used to dye cellulosicblends of the nitrile alloy fibers and certain aciddyestuffs withproteinous blends. In any case, the precise quantity of the reservingagent that is necessary to be applied or used in the treatment for anyparticular purpose can be quickly and readily determined by relativelysimple and straightforward control testing techniques.

The treated nitrile alloy fiber products prepared in I accordance withthe present invention have the same physical properties as theiruntreated counter-parts and have the added features of controlled dyeshades, of resistance to caustic discoloration and of stain resistanceafter dyeing. In this connection, an amount of the reserving agent usedin the treatment (and not necessarily permanently retained) that isbetween about 0.5 and 2 percent by weight, based on the weight of theresulting fiber product, is generally preferred to secure optimumcaustic stability in the treated nitrile alloy fiber products.

The reserving agents for the present invention are, as

indicated, at least partially and to a detectable degree ad-.

herescent upon and substantiative to the nitrile alloy" fibers and, onceapplied, remain in at least minute quantities on the fiber in agenerally permanent manner throughout the normal usages and exposures towhich the fiber may be put. In general, the permanently retainedquantities of the dye reserving or resisting agents have no excessivedeleterious effect or intolerable influence on the physical or aestheticcharacteristics and properties of the fibers on which they are appliedand may ordinarily be employed for many of a wide variety of uses withrelative impunity in this regard. Of course, certain of the propertiesof the treated fiber may vary with the employment of particular treatingagents and the quantity of the agent utilized in and permanentlyretained by the fiber from any given treatment.

j In addition to using'the agents for purposes of stabilizing oraugmenting the resistance to staining by dyestuffs and the like ofuncolored nitrile alloy" fibers, the agents may be frequently employedwith considerable benefit upon already dyed or colored articles of thefiber to increase or establish their resistance to undesired staining oradditional coloration from various sources. Such stain-proofingtreatment, incidentally, may also be made on dyed or otherwise colorednitrile alloy fibers that have been pretreated, prior to dyeing, withlesser, dyeaccepting, modifying or mere color reserving" or balancingapplications or doses of the agent in quantities insufiicient to achievea total or absolute (or practically so) dyeing or coloration-resistingeffect. In addition, as is apparent, the reserving agents may also beused with great advantage for producing white effects in fiber mixturesin piece dyeing, such as may be accomplished by depositing or printingthe reserving agents on the nitrile alloy cloth or fabric goods beingdyed, followed by the piece dyeing operation.

The reserving or dye-resisting agents of the present invention, as hasbeen indicated, are capable of achieving excellent results with manydyestuffs, especially with direct types of dyes and certain acid dyes,on nitrile alloy fibers.

The halogen-substituted mono-aromatic phenolic reserving agents that'areso advantageously employed in combination with the nitrile alloy fibersin the practice of the present invention are of'the structural formulawhereineach-X is independently chlorine or bromineand R is chlorine;bromine; fluorine; hydroxy; (-OH); methyl '(-CH ethyl (-C H and otheralkyl substituents containing up to about 4 carbon atoms; 1 to 4 carbonatom alkoxy radicals such as methoxy (--OCH and partly or completelyhalogen substituted alkyl substituents containing halogens of atomicnumber from 9 to 35 and from 1 to about 4 carbon atoms such astrifluoromethyl (-CF trichloromethyl (CCl etc.; and the like.Advantageously, such compounds as tetra bromo-o-cresol, tetra-chloropyrocatechol, pentachloro phenol, penta-bromo-phenol, 3,5-dibromo-2,4,6-trichloro phenol, and the like are utilized as reserving agents in thepractice of the present invention.

It is advantageous for the applicating formulation or composition of thedye-resisting agent that is utilized for deposition of the latter uponthe nitrile alloy fibers to contain between about 0.1 and 20 percent byweight, based on the weight of the fiber, of the dissolved or disperseddye-resisting agent, depending on the precise quantity of the agent thatmay be desired to be deposited in or. at least employed for treatment ofthe fiber. The actual concentration of the agent with respect to theliquid medium in which it is applied may be much less :than the aboveindicated values. highly effective in their result on the nitrile alloyfibers, their precise concentration with respect to the liquid vehiclein the applicating formulation is relatively immaterial. Generally, theprecise concentration of the reserving agent in the liquid vehicletherefor contained in the applicating formulation is not an essentialcriticality in the practice of the present invention. In most instances,however, it is unnecessary for the applicating formulations to containmore than about 5 percent of the dye-resisting agent, based on theweight of the dry fiber used and depending on the type of dyeingprocedure to be employed. Suitable application of the dye-resistingagent may be made when the liquor-to-fiber ratio of the applicatingformulation to the nitrile alloy fiber being treated is between about 1and 100 parts by weight of the former to .eachpart by weight of thefiber. More often, it is advantageous for such liquor-to-fiber ratio tobe betweenabout 2:1 and 50:1, respectively.

'Various techniques may be utilized for preparing suitable applicatingformulations of the dye-reserving or resisting agent. Usually, as isapparent, it is advantageous to apply it from an aqueous liquiddispersion or solution,

particularly a basic solution containing minor propor-. tions of sodiumhydroxide or other caustic ingredients.

Such a dispersion may be prepared by making preliminary or preparatorysolution of the dye-resisting agent in a liquid in which it is soluble(such as aqueous sodium hydroxide or other caustic solution or loweraliphatic alcohols or ketones) and then diluting the initially preparedsolution with the desired quantity of the water to prepare the finalformulation. Most advantageously, especially when the reserving agentsare used in conjunction with dyeingtreatments on the fiber, theapplicating formulation may be prepared and employed directly as part ofthe liquid vehicle or bath in which the fibers are contained during thedyeing. Thus, if it is intended to apply the resisting agent prior todyeing, the applicating formulation may be prepared and used fortreatment with the resisting agent as well as to constitute the body ofthe dye bath in which the dyeing treatment is accomplished.

In an analogous manner, the dye-resisting agents may be added to dyedfibers in intermediate stages or after completion of dyeing byincorporating them in the dye bath during the dyeing treatment or afterthe dyeing has been accomplished, depending upon the particular purposefor which the agent is being employed. When aqueous caustic solutions,such as aqueous sodium hydroxide solutions, are used as the dispersingvehicle for the agent, it is generally of benefit for the strength ofthe solution to be such. that its pH is between about 8 and 13.

Since the agents are In addition to the procedures mentioned in the foregoing, the dye-resisting agents may also be applied toy or used fortreating the fibers from their applicating formulations by distributingthe formulation, somewhat in the manner of conventional textile finishapplication, directly to a running strand of the nitrile alloy fiberbeing treated, using a liquid jet or spray of the formulation. Ifdesired, applicating rollers and equivalent devices may be utilized forsuch purpose. When the dyeresisting agents are being applied to or fortreating nitrile alloy articles, including articles prepared from fiberblends that are in the form of cloth or fabric, the applica-' tion maybe made during any stage of manufacture or dyeing of such article, usingprocedures analogous to those herein described and demonstrated. Whencloth and fabric are being treated, it may frequently be most convenientfor the application to be made in a manner analogous to conventionalpadding treatments.

In order to further illustrate the invention, but without being limitedthereto or restricted thereby, the following examples are given wherein,unless otherwise indicated, all parts and percentages are to be taken ona weight basis.

EXAMPLE 1 A uniform blend of about parts of viscose rayon fibers and 100parts of nitrile alloy" fibers was prepared, spun into yarn and madeinto knit cloth from which several individual five gram samples wereobtained. The nitrile alloy synthetic fibers in the blend were about 3denier fibers in staple lengths of about 1% inches. They were comprisedof polyacrylonitrile in which there was uniformly incorporated about 8percent, on the weight of the fiber (o.w.f.), ofpoly-N-vinyl-2-pyrrolidone (PVP), having a Fikentscher K-value of about55. The

viscose rayon yarn was a dull yarn having a staple length of about 1%inches and a denier of about 3.

The reserving action of tetra-bromo-o-cresol, tetrachloro-pyrocatecholand penta-chloro-phenol on the cloth samples of the blend were tested byfirst dissolving 0.4 gram of each of the halogen substitutedmono-aromatic phenolic compounds in 1 cc. of 40 percent aqueous sodiumhydroxide, then diluting the resulting solution to a volume of 100 ccs.with water. Separate samples of the knit blend were then impregnatedwith and treated by means of each of the solutions for 30 minutes atabout 40 C. The fibers were then dyed in the conventional manner with 2percent Cibanone Blue GF, a vat dyestufi (Colour Index 1113 or Vat Blue6). The nitrile alloy" fibers in the blend remained essentially whitewhile the viscose component dyed to a distinct blue shade of coloration.

In contrast, when the foregoing was repeated, excepting to eliminate thepreliminary applications of the reserving agents the full depth dyeingof both types of fibers in each of the blended samples was obtained.

EXAMPLE 2 Two separate five gram samples of the same knit blends of thenitrile alloy fiber and viscose rayon employed in the first example werescoured for 30 minutes at 70 C. in a 1 percent aqueous solution ofIgepon T (an anionic detergent obtained from General Aniline and FilmCorporation which is sodium N-methyl-N-oleoyl taurate). The samples werethen placed in a Laundrometer (a commercial wash-fastness testingapparatus consisting of a set of jars in which textile samples areplaced with a solution of a detergent, the jars being rotated so theyare immersed in hot water for at least half of the rotating cycle)wherein one of the samples was impregnated with a 0.25 gram solution ofpenta-bromophenol prepared as in the first example and the other with asimilar strength solution of 3,5-dibromo-2,4,6-trichloro-phenol for 15minutes at F. At the end of this time, about 1.5 grams of Cibanone GreenBF, a vat dyestufi, (Colour Index 1101 or Vat Green 1) was addedassassto each solution and the resulting" so utions maintained at the's'a me temperature for an additional 45 minutes. The samples" were thenremoved from the dye b'ath's', rinsed thoroughly with water, treatedwith one ml of 30 percent aqueous hydrogen peroxide and 2 ml. of 10percent acetic acid (while the samples were contained in a water bathhaving a volume of about 150 ccs.), dried at 80 C., scoured with 1percent o.w.f. of Igepon T in aqueous solution-and again rinsed anddried. Again, the dye-receptivity of the nitrile alloy fiber componentin each of the; knit blends was quite beneficially altered in a readilyapparent and visually discernible manner while the viscose rayoncomponents were dyed to deep and level shades of coloration.

EXAMPLE 3 One molar solutions of various phenolic compounds in alcoholwere prepared, vTen ml. of each of the resulting solutions were thenmixed with 10 ml. of one molar NaOH and the resulting solutions dilutedto 100 ml. with water. A caustic test solution was prepared by addingabout 80 ml. of 40 percent aqueous NaOH to 41 ml. of water. To separate100 ml. volumes of caustic test solution, there was added separate 10-,25-, and 50- volumes of each of the phenolic solutions that had beenprepared. The pH of the resulting solutions ranged from about 12.6 to12.9. Five gram samples of the same unblended nitrile alloy fiber asemployed in the first example were then added to each solution andmaintained at 160 C. for one hour. The samples were rinsed, dried andthen observed for discoloration using a Beckman spectrophotometer. Theresults are given in Table 1 wherein each of the phenolic materialsemployed is also identified. Thepercent color is a measure of thediscoloration caused bythe basic solutions using a reference of 100percent discoloration of the fiber when no' reservingagent was employedto lend its stabilizing effect against caustic'thereto.

About. 0.2 gram of penta-chloro phenol was dissolved in an alkalinesolution of caustic in water (pH 9) and heated to 70 C. A two gramsample of a blend of 50 percent by weight of the nitrile alloy fiberemployed in the first example and 50 percent by weight of middlingcotton staple was dyed with Calcodur Pink 2BL, a direct dyestufi (ColourIndex 353), water-washed and dried. The cotton dyed a bright pink butthe nitrile alloy fiber remained white, being neither dyed or discoloredby the caustic solution.

In contrast, when the untreated nitrile alloy fiber isdyed with the samedyestuif, deep and level shades of coloration are readily obtainedtherein.

EXAMPLE A five gram sample of the same nitrile alloy fiber as employedin the first example was treated, in an unblended condition, with analkaline solution containing about 0.5 gram of penta-chloro phenoldissolved ina mixture of 0.2 gram NaOH and 50 ml. of water. After thesample was washed and dried, it was immersed in a solution of Food Drugand Cosmetic No. 1 (a food dye). The fiber was initially colored by thedyestutf but'the eoloration was "easily washed out of'the treatedfiberso as tollave, after washing, a whiteand unstained-fiber product;

' V EXAMPLE 6 The procedures of each of the five preceding examples isrepeated excepting to use a nitrile alloy fiber comprised ofpolyacrylonitrile containing normally solid poly- N-vinyl-2-caprolactamas the dye-assisting adjuvant in place of the PVP. Identical results areachieved. Likewise, identical results are achieved with nitrile alloyaromatic phenolic reserving agents indicated to be withinthe scope ofthe invention are utilized in place of those specifically illustrated.Excellent results may also be achieved when the resistingagents areapplied on unmixed or unblended nitrile alloy fibers for purposes andapplications where such technique and manner of treatment is desirableand indicated. Commensurate results may likewise be achieved when otherblends of the nitrile alloy fibers, including blends with cellulosicsother than cottonor viscose rayon yarn (such as cuprommonium rayon yarn,cellulose acetate and the like cellulose esters and other cellulosefibers of natural or synthetic or artificial origin) as well as blendsof the nitrile alloy fibers with various proteinous fibers of natural orsynthetic origin, including wool, silk fibers, zein-protein fibers (suchas those that are commercially available under the trade name Vicara)feather-keratin, casein fibers, protein fibers and the like proteinousor so-called Azlon fibers of natural, artificial, regenerated orreconstituted origin.

As has been indicated in the foregoing, the nitrile alloy" fibers arecomprised essentially of the mentioned acrylonitrile polymer base whichhas been modified or alloyed with beneficial additaments or constituentswhich are adapted and calculated to provide the fiber product with itspeculiar and unusually advantageous properties. Variousbeneficialadditaments or constituents that are capable of securing the desirablecharacteristics of which the nitrile alloy fiber is possessed may be ofany of several diverse types. For example, the beneficial constituentmay be derived from and originate with a monomer or mixture of monomers,capable of being converted 'to a dye-receptive and possibly otherwisefunctional polymer product, which is graft or block copolymerized to andupon the already formed (and, with advantage, already fabricated)acrylonitrile polymer base. Alternatively, and witl1 equal advantage,the beneficial constituent may be a dye-receptive and possibly otherwisefunctional; polymeric product with which the essential acrylonitrilebase is graft or block copolymerized by graft copolymeriz'ation ofacrylonitrile or an acrylonitrile monomer mixture on or with the alreadyformed functional polymer in order to furnish the fiber-forming polymerproduct of which the nitrile alloy fiber is composed. Or, as a suitableand frequently quite satisfactory alternative, the already formedbeneficial additaments or constituents in the ,nitrile alloy fiber maybe in the nature of polymeric adjuvants that are physically blended andintimately incorporated by any of several suitable procedures with theessential acrylonitrile polymer base. Such adjuvants may behomopolymeric, copoiymeric or graft copolymeric substances which serveto augment at least the dyeability of the normally difiicult (if notimpossible) to dye acryloni' 'trile polymer base.

Amongst the most beneficial and advantageous of the nitrilealloy fibersare those that are comprised of the essential acrylonitrile polymerbase, particularly polyacrylonitrile, in which there has been'intimatelyand permanently" or substantially permanently incorporatedminorproportions of from 1 'or so up to about 20 or so percent by weight,based on the weight of the nitrile alloy composition, of any of thebeneficial additaments or constituents adapted to serve the desiredpurpose and provide the beneficial result. Generally, such beneficialadditaments are employed primarily as dye-assisting adjuvants orcomponents. Advantageously, they may be the polymerized products of suchazotic monomers, or mixtures thereof, as the several N-vinyl lactamsincluding such broadly related products as the N-vinyl-3,-morpholinones;the N- vinyl-2-oxazolidinones; and certain of the N-vinyl-N-methyl-alkylsulfonamides. Thus, the nitrile alloy may be comprised ofthe acrylonitrile polymer base that is prepared by graft or blockcopolymerization of acrylonitrile or an acrylonitrile-containing monomermixture upon a minor proportion of an already formed polymer derivedfrom any of the indicated varieties of azotic monomers or theirmixtures. Or, as mentioned, it may consist of a graft copolymer productof any of the indicated varieties of azotic monomers on an alreadyformed and preferably already fabricated acrylonitrile polymer base.Advantageously, and frequently with consumate suitability, the nitrilealloy fiber may be comprised of the acrylonitrile polymer base in whichthere is permanently incorporated by physical blending a minorporportion of any of the polymer products from the specified azoticmonomers or mixtures thereof, primarily as dyeassisting adjuvants.

Such species of nitrile alloy" fibers are capable of being accuratelydescribed as synergetic and anisotropic clathrates that are composed ofa hydrophobic polymer in combination with a hydrophilic polymer. ties ofthe nitrile alloy fibers (as well as in other of the forms in which theymay be obtained) there is a mutually enhancing cooperative union of ahighly crystalline polymer which provides strength, durability, wrinklerecovery and high melting point in the fibers with an unusuallynon-ionic polychelate that provides dye-receptivity as well as moistureregaining powers for the fiber and other aesthetic' characteristics thatlend to the wearing comfort oftextile goods manufactured from the fiber.The nitrile alloy fibers have been described by G. W. Stanton in anarticle entitled Zefran appearing in the Textile Research Journal,volume XXVII, No. 9, for September 1957, pp. 703-712. They have alsobeen recognized as a distinct class of man-made synthetic textile fibersin Textil Organon, September 1956, at pages 129-130.

As indicated, the adjuvant or beneficial constituent in the nitrilealloy fiber may be homopolymeric in nature or it may be a straightcopolymer of any of the azotic monomers specified with other monoandpolyfunctional monomers. Adjuvants of this variety are ordinarilyphysically blended with the essential acrylonitrile polymer base inorder to secure the desired intimate incorporation of the beneficialconstituent and the resulting alloying effect in the fiber. Likewise,there may be similarly utilized for physical blending purposes adjuvantsor additaments that are graft copolymeric in nature and which consist ofvarious monomers that are graft copolymerized on substrates consistingof polymers of any In such variecent by weight, based on the weight ofthe nitrile alloy: composition. It is frequently quite desirable toemploy a homopolymeric N-vinyl lactam' polymer, such aspoly-N-vinylpyrrolidone (which may also be identified as polyN-vinyl-Z-pyrrolidone or, with varied terminology, poly-N-vinyl-Z-pyrrolidinone), poly-N-vinyl caprolactam, or somewhat relatedthereto, a poly-N-vinyl-3-morpholinone;

. or a homopolymeric N-vinyl-Z-oxazolidinone or poly-N- of the indicatedazotic monomers, such as poly-N-vinylcomponent in nitrile alloy fibersin an amount that is in the neighborhood or range of from about 5 to 15pervinyl-5-methyl-2-oxazolidinone; or a homopolymeric N-vinylmethylalkylsulfonamide polymer such as homopolymericNv-vinyl-N-methyl-methylsulfonamide; as the polymeric adjuvant that isblended with the essential acrylo-, nitrile polymer base in the nitrilealloy composition. When physically blended nitrile alloy products areprepared that utilize, as the beneficial additament or constituent,copolymeric or graft copolymeric products of the indicated azoticmonomers, it is usually beneficial for the polymeric adjuvants that areemployed to be' those which are comprised of at least about 50 percentor even as much as or more percent by weight of the products of theindicated constituents derived from the azotic monomers.

In addition to products of N-vinyl-pyrrolidone or N- vinyl caprolactam,other of the N-vinyl (or l-vinyl) lactams which may be utilized includeany of those (ortheir mixtures) that have been described or which areinvolved in US. Patents Nos. 2,265,450; 2,355,454 and 2,371,804.Particular mention may also be made of N- vinyl-5 methyl-pyrrolidone;N-vinyl-3,3-dimethyl gamma valerolactam; and N-vinyl piperidone.Particular mention may also be made of somewhat related products derivedin any of the ways described from N-vinyl-3- morpholinones of thestructure:

wherein each substituent R unit is independently selected from the groupconsisting of hydrogen, 1 to about 4 carbon alkyl radicals, 6 to about10 carbon aryl radicals and equivalents thereof.

Similarly, besides unsubstituted N-vinyl-Z-oxazolidinone, other N-vinyl(or 3-vinyl)-2-oxazolidinone products which may be used as polymericadjuvants include those derived from monomers represented by theformula:

HC=CH2 in which at least one of the substituent R R R or K; groups, whenit is not hydrogen, may be a 1 to about 4 carbon atom alkyl. radical ora 6.to about 10 carbon atom aryl radical or their equivalents. Typicalsof such monomers may be mentioned N-vinyl-S-methyl-2-oxazolidinone;N-vinyl-5-chloromethyl-Z-oxazolidinone;N-vinyl-4,5-dimethyl-Z-oxazolidinone, N-vinyl-5-ethyl-2-ox azolidinone;N-vinyl-5-phenyl-2-oxazolidinone; and the like.

The N-vinyl-N-methyl-alkylsulfonamide 7 monomers whose polymericproducts may be advantageously utilized for the, nitrile alloys includethose represented by the.- formula:

wherein Ris hydrogen, a 1 to about 4 carbonv alkyb radical, a" 6 toabout 10 carbon-aryl radical or some equivalent thereof.

Suitable nitrile alloy" products may also be manufa'c tured from otherbeneficial additaments or components that are more or'less equivalent tothose derived from the azotic monomers indicated in the foregoing. Thus,other varieties of N-heterocyclic monomers more or less similar orrelated to the specified N-2-propenyl types and analogous related azoticcompounds may'freque 'ntly be employed in combination with or to'replace the several beneficial additaments or constituents th'at havebeen delineated.

What is claimed is:

l. A synthetic textile fiber which is characterized in having itsnormally receptivity to dyestuffs modified so" as to have dye-resistingcharacteristics, said fiber being selected from the class ofsynthetictextile fibers consist ing of (A) intimate polymer blendscomprised essentially of (A1) between about 80 and about 99 weightpercent, based on dry fiber weight, of a fiber-forming acrylonitrileaddition polymerwith (A2) between about 20 and about 1 weight percent,based on dry fiber weight, of an azotic' polymeric dye-assistingadjuvant selected from the group consisting of addition polymers of atleast about 50 weight percent, based on the weight of the azoticpolymer, of (A2a) N-vinyl lactam monomers; (A2b) n-vinyl-3- morpholinonemonomers of the structure:

uo Eon RCH 0:0

acme, wherein each substituent R unit is independently selected from thegroup consisting of hydrogen, 1 to about 4 carbon atom alkylsubstituents and 6 to about 10 carbon atom aryl substituents; (A2c)N-vinyl-2-oxazolidinone monomers of the structure:

11 -0%? Ra-C 0=0 H(I]=CH: in which R R R and R are independentlyselected from the group consisting of hydrogen, 1 to about 4 carbon atomalkyl substituents and 6 to about 10 carbon atom aryl substituents;(A2d) N-vinyl-N-methyl-alkylsulfonamide monomers of the structure:

wherein R is selected from the group consisting ofhydrogen, l to about 4carbon atom alkyl substituents and 6 to about 10 carbon atomaryl'substituents; and (A2e) mixtures thereof; (B) fiber-forming graftcopolymers comprised essentially of (B1) between about 80 and about 99weight percent, based on dry fiber weight,- of a pre-formedfiber-forming acrylonitrile addition polymer; substrate with graftcopolymerized substituents thereon of (B2) between about 20 and about 1weight percent, based on dry fiber weight, of additionpolymerized'azo'tic monomer substituents of at least about 50 weightpercent, based on the weight of graft .copolymerized subs't'ituerit', of(B2a) N-vinyl lactam monomers; (B2b) said N-vinyl- 3-tnorpholinonemonomers; (820) said N-vinyl-2-oxazolidinone monomers; (B2d) saidN-vinyl-N-methyl-alkylsulfonamide monomers; and (B2e) mixtures thereof;and (C) fiber-forming graft copolymers comprised essentially of (C1)between about 80 and 99 weight percent, based on dry fiber weight, ofacrylonitrile graft copoly 7 merize'd on (C2) between about 20 and about1 weight percent, based on dry fiber weight, of a pre-formed,dyemssisting, azotic addition polymer substrate of at least about'50weight percent, based on' the weight of said substrate, of (C2a) N-vinyllactam monomers; (C2b) said N-vinyl-3-morpholinone monomers; (C2a) saidN- vinyl-2-oxazolidinone monomers; (C2d) said N-vinyl-N-methylalkylsulfonarnide monomers; and (C2e) mixtures thereof, said fibercontaining as a dye-reserving and resisting agent effective againstdirect, acid and vat dyestuffs between about 0.1 and25 weight percent,based on the weight of the fiber, of which at least about 0.01 weightpercent is permanently and substantiatively retained by said fiber, of acompound having the structure:

wherein each X is independently selected from the group consisting'ofchlorine and bromine and R is selected from the group consisting ofchlorine, bromine, fluorine, hydroxy, alkyl radicals containing from 1to about 4 carbon atoms, halogen substituted alkyl radicals containinghalogens of atomic number from 9 to 35 and from 1 to about 4 carbonatoms, and alkoxy radicals containing from 1 to about 4 carbon atoms.

2. The treated fiber of claim 1, having from about 0.1 toabout 1.5percent by weight of said reserving agent initially applied thereon andcharacterized in having relatively slight resistance to becoming stainedupon contact with dyestuffs.

3. The treated fiber of claim 1 having from about 1.5 to 10 percentby'weight of said reserving agent initially applied thereto andcharacterized in having a moderate reserving action to becoming stainedupon being contacted with dyestuffs.

4. The treated fiber of claim 1, having from about 10 to 25 percent byweight of said reserving agent initially applied thereon andcharacterized in having a substantially complete resistance to becomestained upon contact with dyestuffs.

5. The treated fiber of claim 1 contained in a blend of fibers withcellulose fibers.

6. A blend of fibers in accordance with the blend set forth in claim 5,wherein said cellulosic fibers are cotton.

7. A blend of fibers in accordance with the blend set forth in claim 5,wherein said cellulosic fibers are viscose rayon;

8. The treated fiber ofclaim 1 contained in a blend of fibers withproteinous fibers.

9. A blend of fibers in accordance with the blend set forth in claim 7,wherein said proteinous fibers are wool.

10. The treated fiber of claim 1, wherein said synthetic fiber containsfrom about 1 to about 20 percent by weight, based on the weight of thefiber, of polymerized N-vinyl lactam monomer.

11. The treated fiber of claim 1, wherein said synthetic fiber containsfrom about 1 to about 20 percent by weight, based on the weight of thefiber, of polymerized N-vifiyl-Z-oxazolidinone monomer.

I 12. The treated fiber of claim 1, wherein said synthetic fibercontains from about 1 to about 20 percent by weight, based on the weightof the fiber, of polymerized N-vinyl- 3-morpholinone monomer.

13. The treated fiber of claim 1, wherein said synthetic fiber consistsof an intimate polymer blend of polyacrylonitrile and from about 1 toabout 20 percent by weight, based on the weight of the fiber, ofpoly-N-vinyl-2-pyrrolidone as a dye-assisting adjuvant.

14. The treated fiber of claim 1, wherein said synthetic fiber consistsof an intimate polymer blendof polyacrylonitrile and from about 1 toabout 20 percent by weight,

based on the weight of the fiber, of poly-'N-vinylcaprolactam as adye-assisting adjuvant.

15. The treated fiber of claim 1, wherein said syn thetic fiber consistsof an intimate polymer blend of polyacrylonitrile and from about 1 toabout 20 percent by weight, based on the weight of the fiber, of poly-N-yinyl-S-methyl-Z-oxazolidinone as a dye-assisting aduvant.

16. The treated fiber of claim 1, wherein said synthetic fiber consistsof an intimate polymer blend of polyacrylonitrile and from about 1 toabout 20 percent by Weight, based on the weight of the fiber, of poly-N-vinyl-3-morpholinone as a dye-assisting adjuvant.

17. The treated article of claim 1, wherein said dyereserving agent istetra-bromo-o-cresol.

18. The treated article of claim 1, wherein said dyereserving agent istetra-chloro-pyrocatechol.

19. The treated article of claim 1, wherein said dyereserving agent ispenta-chloro-phenol.

20. The treated article of claim 1, wherein said dyereserving agent ispenta-bromo-phenol.

21. Treatment for a synthetic fiber to reduce its receptivity todyestutfs, said fiber being selected from the class of synthetic textilefibers consisting of (A) intimate polymer blends comprised essentiallyof (A1) between about 80 and about 99 weight percent, based on dry fiberweight, of a fiber-forming acrylonitrile addition polymer with (A2)between about 20 and about 1 weight percent, based on dry fiber weight,of an azotic polymeric dye-assisting adjuvant selected from the groupconsisting of addition polymers of at least about 50 weight percent,based on the weight of the azotic polymer, of (A2a) N-vinyl lactammonomers; (A2b) N-vinyl-3-morpholinone monomers of the structure:

me sort Ros 0=o HO=CH2 wherein each substituent R unit is independentlyselected from the group consisting of hydrogen, 1 to about 4 carbon atomalkyl substituents and 6 to about 10 carbon atom aryl substituents;(A2c) N-vinyl-2-oxazolidi none monomers of the structure:

Ego- 0 14 in which R R R and R are independently selected from the groupconsisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and6 to about 10 carbon atom aryl substituents; (A2d)N-vinyl-N-methyl-alkylsulfonamide monomers of the structure:

0 ll R?=O NCHa HC=OH2 wherein R is selected from the group consisting ofhydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10carbon atom aryl substituents; and (A2e) mixtures thereof; (B)fiber-forming graft copolymers comprised essentially of (B1) betweenabout 80 and about 99 weight percent, based on dry fiber weight, of apre-formed fiber-forming acrylonitrile addition polymer substrate withgraft copolymerized substituents thereon of (B2) between about 20 andabout 1 weight percent, based on dry fiber weight, of additionpolymerized azotic monomer substituents of at least about weightpercent, based on the weight of graft copolymerized substituent, of(132a) N-vinyl lactam monomers; (B2b) said N-vinyl-3-morpholinonemonomers; (B20) said N- vinyl-2-oxazolidinone monomers; (B2d)' saidN-vinyl-N- methyl-alkylsulfonamide monomers; and (B2e) mixtures thereof;and (C) fiber-forming graft copolymers comprised essentially of (C1)between about and 99 weight percent, based on dry fiber weight, ofacrylonitrile graft copolymerized on (C2) between about 20 and about 1weight percent, based on dry fiber weight, of a pre-formed,dye-assisting, azotic addition polymer substrate of at least about 50weight percent, based on the weight of said substrate, of (02a) N-vinyllactam monomers; (C2b) said N-vinyl-3-morpholinone monomers; (C2c) saidN-vinyl-2-oxazolidinone monomers; (C2d) saidN-vinyl-N-methyl-alkylsulfonamide monomers; and (C29) mixtures thereof,which treatment comprises initially applying to the fiber between about0.1 and 25 weight percent, based on the weight of the fiber, of adye-reserving agent efiective against direct, and vat dyestufis asdefined by Formula I in claim 1.

References Cited in the file of this patent OTHER REFERENCES Sandoz:J.S.D.C., vol. 66, October 1950, p. 564.

1. A SYNTHETIC TEXTILE FIBER WHICH IS CHARACTERIZED IN HAVING ITSNORMALLY RECEPTIVITY TO DYESTUFFS MODIFIED SO AS TO HAVE DYE-RESISTINGCHARACTERISTICS, SAID FIBER BEING SELECTED FROM THE CLASS OF SYNTHETICTEXTILE FIBERS CONSISTING OF (A) INTIMATE POLYMER BLENDS COMPRISEDESSENTIALLY OF (A1) BETWEEN ABOUT 80 AND ABOUT 99 WEIGHT PERCENT, BASEDON DRY FIBER WEIGHT, OF A FIBER-FORMING ACRYLONITRILE ADDITION POLYMERWITH (A2) BETWEEN ABOUT 20 AND ABOUT 1 WEIGHT PERCENT, BASED ON DRYFIBER WEIGHT, OF AN AZOTIC POLYMERIC DYE-ASSISTING ADJUVANT SELECTEDFROM THE GROUP CONSISTING OF ADDITION POLYMERS OF AT LEAST ABOUT 50WEIGHT PERCENT, BASED ON THE WEIGHT OF THE AZOTIC POLYMER, OF (A2A)N-VINYL LACTAM MONOMERS, (A2B) N-VINYL-3MORPHOLINONE MONOMERS OF THESTRUCTURE: